WD external hard drive 1.5 TB does not work

I needed an 800 firewire, so I could use this external for video editing. After 1 month it started not to show up on my desktop on my new macbook pro. I have tried many ways to see what is wrong. The power is working too. I go to my utility and it's icon is not there. What do I need to do please. I have some important stuff. I did go to best buy to maybe buy a shoe for it, but they only have shoes for USB port.
Thanks in advance